A feral cat or a stray cat is an unowned domestic cat that lives outdoors and avoids human contact; it does not allow itself to be handled or touched, and usually remains hidden from humans. Feral cats may breed over dozens of generations and become an aggressive local apex predator in urban, savannah and bushland environments. Some feral cats may become more comfortable with people who regularly feed them, but even with long-term attempts at socialization, they usually remain aloof and are most active after dusk. Of the 700 million cats in the world, an estimated 480 million are feral.

A free-ranging dog is a dog that is not confined to a yard or house. Free-ranging dogs include street dogs, village dogs, stray dogs, feral dogs, etc., and may be owned or unowned. The global dog population is estimated to be 900 million, of which around 20% are regarded as owned pets and therefore restrained.